linux-kernel - Re: [PATCH 1/3] hwmon: spd5118: Do not fail resume on temporary I2C errors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <c36306c5-2426-4a9c-9abd-9f3cdab17ed5@roeck-us.net>
Date: Mon, 12 Jan 2026 08:30:22 -0800
From: Guenter Roeck <linux@...ck-us.net>
To: Tinsae Tadesse <tinsaetadesse2015@...il.com>
Cc: linux-hwmon@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] hwmon: spd5118: Do not fail resume on temporary I2C
 errors

On 1/10/26 09:19, Tinsae Tadesse wrote:
> SPD5118 DDR5 temperature sensors may be temporarily unavailable
> during s2idle resume. Ignore temporary -ENXIO and -EIO errors during resume and allow
> register synchronization to be retried later.
> 
> Signed-off-by: Tinsae Tadesse <tinsaetadesse2015@...il.com>
> ---
>   drivers/hwmon/spd5118.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/spd5118.c b/drivers/hwmon/spd5118.c
> index 5da44571b6a0..ec9f14f6e0df 100644
> --- a/drivers/hwmon/spd5118.c
> +++ b/drivers/hwmon/spd5118.c
> @@ -512,9 +512,15 @@ static int spd5118_resume(struct device *dev)
>   {
>   	struct spd5118_data *data = dev_get_drvdata(dev);
>   	struct regmap *regmap = data->regmap;
> +	int ret;
>   
>   	regcache_cache_only(regmap, false);
> -	return regcache_sync(regmap);
> +	ret = regcache_sync(regmap);
> +	if(ret == -ENXIO || ret == -EIO) {
> +		dev_warn(dev, "SPD hub not responding on resume (%d), deferring init\n", ret);
> +		return 0;
> +	}
> +	return ret;
>   }
>   
>   static DEFINE_SIMPLE_DEV_PM_OPS(spd5118_pm_ops, spd5118_suspend, spd5118_resume);


Based on the subsequent exchange, this is not the appropriate solution.
The problem is that the i2c controller suspends too early. It should suspend
later instead. Alternatively, this driver should suspend early, but it does
not look like respective PM operations are available.

I would suggest to try replacing DEFINE_SIMPLE_DEV_PM_OPS() in drivers/i2c/busses/i2c-i801.c
with SET_LATE_SYSTEM_SLEEP_PM_OPS() or similar.

Guenter